On your marks, get set, bake! It’s a double dose of spice this holiday season when the most festive and friendliest competition on television returns with new host, Emma Bunton (Spice Girls), Anthony “Spice” Adams, veteran judge Paul Hollywood (“The Great British Bake Off”) and new judge, three-time James Beard Award-winning pastry chef Sherry Yard, when Season 4 of “The Great American Baking Show: Holiday Edition” premieres with slices of cake, and sweet and savory pastries.